<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <title>姓名案例_methods实现</title>
  <script src="../js/vue.js"></script>
</head>

<body>
  <div id="root">
    姓：<input type="text" v-model="firstName"><br />
    名：<input type="text" v-model="lastName"><br />
    全名：<span>{{fullName()}}</span>
  </div>

  <script>
    Vue.config.productionTip = false

    new Vue({
      el: '#root',
      data: {
        firstName: '张',
        lastName: '三'
      },
      methods: {
        fullName() {
          return this.firstName.slice(0, 3) + '-' + this.lastName
        }
      }
    })
  </script>
</body>

</html>